bignum_mod_raw.py: Added BignumModRawOperation

This patch is adding a basic instantance of `BignumModRawOperation`
and creates an `BignumModRawOperationArchSplit` class, copying
over the implementation of `BignumCoreRawOperationArchSplit`.

Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
diff --git a/scripts/mbedtls_dev/bignum_mod_raw.py b/scripts/mbedtls_dev/bignum_mod_raw.py
index 2e059b2..1127ced 100644
--- a/scripts/mbedtls_dev/bignum_mod_raw.py
+++ b/scripts/mbedtls_dev/bignum_mod_raw.py
@@ -15,8 +15,11 @@
 # limitations under the License.
 
 from abc import ABCMeta
+from typing import Dict, Iterator, List
 
+from . import test_case
 from . import test_data_generation
+from . import bignum_common
 
 class BignumModRawTarget(test_data_generation.BaseTarget, metaclass=ABCMeta):
     #pylint: disable=abstract-method
@@ -48,7 +51,42 @@
 # END MERGE SLOT 6
 
 # BEGIN MERGE SLOT 7
+class BignumModRawOperation(bignum_common.OperationCommon, BignumModRawTarget, metaclass=ABCMeta):
+    #pylint: disable=abstract-method
+    pass
 
+class BignumModRawOperationArchSplit(BignumModRawOperation):
+    #pylint: disable=abstract-method
+    """Common features for bignum core operations where the result depends on
+    the limb size."""
+
+    def __init__(self, val_a: str, val_b: str, bits_in_limb: int) -> None:
+        super().__init__(val_a, val_b)
+        bound_val = max(self.int_a, self.int_b)
+        self.bits_in_limb = bits_in_limb
+        self.bound = bignum_common.bound_mpi(bound_val, self.bits_in_limb)
+        limbs = bignum_common.limbs_mpi(bound_val, self.bits_in_limb)
+        byte_len = limbs * self.bits_in_limb // 8
+        self.hex_digits = 2 * byte_len
+        if self.bits_in_limb == 32:
+            self.dependencies = ["MBEDTLS_HAVE_INT32"]
+        elif self.bits_in_limb == 64:
+            self.dependencies = ["MBEDTLS_HAVE_INT64"]
+        else:
+            raise ValueError("Invalid number of bits in limb!")
+        self.arg_a = self.arg_a.zfill(self.hex_digits)
+        self.arg_b = self.arg_b.zfill(self.hex_digits)
+        self.arg_a_int = bignum_common.hex_to_int(self.arg_a)
+        self.arg_b_int = bignum_common.hex_to_int(self.arg_b)
+
+    def pad_to_limbs(self, val) -> str:
+        return "{:x}".format(val).zfill(self.hex_digits)
+
+    @classmethod
+    def generate_function_tests(cls) -> Iterator[test_case.TestCase]:
+        for a_value, b_value in cls.get_value_pairs():
+            yield cls(a_value, b_value, 32).create_test_case()
+            yield cls(a_value, b_value, 64).create_test_case()
 # END MERGE SLOT 7
 
 # BEGIN MERGE SLOT 8